Oil feeder having restrictor



Aug. -11, 1959 w. M. BOOTH 12,899,018

' OIL FEEDER HAVING RESTRICTOR Filed July 18, 1955 r 3 Sheets-Sheet 1 INV EN TOR.

BY Will/29m M Boat/7 Arr-away Aug. 11, 1959 w. M. BOOTH OIL FEEDERHAVING RESTRICTOR S Sheets-Sheet 2 Filed July 18, 1955 INVENTOR. ByW/Y/I'am M. Boob?- OPNE Y United States Patent OIL FEEDER HAVINGRESTRICTOR William M. Booth, Spring Lake, Mich, assignor' toGardnet-Denver Company, Quincy, IlL, a corporation of DelawareApplication July 18, 1955, Serial No. 522,810

Claims. (Cl. 184-55) This invention relates to pneumatic tools and moreparticularly to a combination filter and lubricator for .conditioningthe operating air by which pneumatic tools and like equipment arepowered.

It is common practice to install a filter or a lubrioator and morecommonly both in the air supply line for pneumatic tools. Heretofore,these have been installed as separate elements or if they have beenjoined they have remained separate and distinct structures connectedonly by a suitable pipe serving as an air passageway such as illustratedin US. Patent 1,990,524. This invention, for the first time, provides afiltering and lubricating device combined and integrated in a singleunit and performing both functions with a substantial improvement inoverall efiiciency over such units operating as separate and distinctcomponents.

This invention also provides an axial flow air filter inserted in themain line along which the air is flowing, thus greatly reducing thenumber of turns the air must make in traversing the filter unit. Thisresults in an appreciable decrease in the pressure drop resulting fromthe use of the filter. I

The combination of the filter and the lubricator in a single unitprovides a compact assembly of substantially lower cost than the twounits manufactured as separate components.

This invention permits the oil chamber or reservoir to be filled withoutshutting off the air supply to the tool and at the same time assuresproper lubrication of the tool during the filling operation.

The unit provides .a device which may be used as either a filter or alubricator unit separately and provides accurate and adjustableregulation of the quantity of oil being fed into the air. While itpermits adjustability, it conceals the adjustment mechanism for the oilfeed in a manner preventing being tampered with by the operators.

These and other objects and purposes of this invention will be fullyunderstood by those acquainted with pneumatic filters and l-ubricatorsupon reading the following specification and the accompanying drawings.

In the drawings:

Fig. 1 is an end elevation view of this invention.

Fig. 2 is an enlarged sectional elevation view taken along the planeIIII of Fig. 1.

Fig. 3 is a sectional view taken along the plane III I II of Fig. 2.

Fig. 4 is a plan view of the funnel used in the collection chamber ofthis invention.

Fig. 5 is an elevation view of the upstream end of the filter elementfor this invention.

Fig. 6 is a central elevation view of the regulator valve between thecollection and oil chambers of this in vention taken along the plane VI-VI of Fig. 7-and showing the ball valve in one operating position.

Fig. 7 is a central sectional view of the regulator valve taken alongthe plane VIIVII of Fig. 6 and showing the ball valve in its oppositeoperating position.

Fig. 10 is an enlarged fragmentary sectional view of a modified form ofthe oil passage structure for this .from one side of the filter to theother.

invention.

Fig. 11 is an enlarged fragmentary sectional view of a further modifiedstructure for the oil passage for this invention.

Fig. 12 is an enlarged fragmentary view of this invention taken alongthe same plane as Fig. 2 but showing a modified form of the invention.

A. Head In executing the objects and purposes of this invention, I haveprovided a combination air filter and lubricato'r having a head throughwhich passes an air passage for the air supplying a pneumaticallyoperated device. Seated in this passageway is a filter. Below the headis a bowl having three chambers, these being a collection chamber, anoil chamber and an oil passage. The collection chamber serves as areceptacle for water and particles collected by the filter. The oilchamber serves as an oil reservoir from which oil is discharged into theoil passageway. An oil feeder is provided between the oil passage, andthe air passage in the head adjacent the discharge port for the passageby which oil is withdrawn from the oil passage and discharged into theair stream. Oil is forced from the oil chamber into the oil feeder by apressure differential existing between the air in the oil chamber andthe air in the air passage at the point where the oil feedercommunicates with it.

Referring specifically to the drawings, the numeral 10 indicates ahousing having a head 11, a bowl 12 and an assembly ring 13 by which thebowl 12 is secured to the head 11.

The head 11 has a diametric air passage14 extending. through it (Fig.2). Approximately midway between the ends of the air passage is ashoulder 15 against which is seated the filter element 16.

The filter 16 is circular, having at its upstream end a radiallyprojecting flange 18 designed to bear against the shoulder 15 and tosupport the filter against the pressure of the air passing through it. Agasket 17 of suitable material such as oil resistant rubber or felt isprovided between the filter 16 and the shoulder 15. The main body of thefilter consists of an outer frustoconically shaped wall 19 and an innerconically shaped wall 20 having its apex directed upstream. Thecombination of the Walls 19 and 20 results in a filter having alongitudinal cross sectional shape somewhat resembling that of a W. Thisparticular arrangement of the walls 19 and 20 provides a large surfacearea through which the air may percolate V This is important to providea filter which will operate with a mini.- mum of pressure drop.

The filter may be made of a number of suitable materials havingsufficient strength to withstand the loads imposed as the result of thepressure drop across the filter. Without invany way intending to limitthe scope of this invention, it is suggested that two materialsparticularly suitable, for this filter are a porous sintered metal and aporous ceramic, both of which should have a structure at least fiftypercent void. v 1

The filter is held inposition andpressed against the shoulder 15 by aspring 21, one end of which bears against the flange 18 and the otherend bears against the collar 22 press-fitted into the inlet end of theair passage .14. The collar 22 is internally threaded to provide aninlet port 23. Between the filter 16 andthe collar 22, the air passage14 opens tbr'ough the bottom of the head by means of the channel 24surrounded, in part, by the bafiie 25.

Downstream of the filter 16, the air passage 14 has a restricted throat30, serving as a Venturi. The restricted throat 30 terminates in athreaded discharge port 31. A threaded passageway 32 opening through thebottom of the head 11 communicates with the air passage 14 closelyadjacent the point of maximum restriction of the throat 30 and betweenit and the discharge port 31.

A cavity is provided in the head between the bafile 2S and the threadedpassageway 32 but separated both from the air passage 14 and thethreaded passage 32. The cavity 33 opens through the bottom of the head.

B. Bowl Below the head is the tertiary chambered bowl 12, having acollection chamber 40, oil chamber 41 and an oil passage 42. Thecollection chamber 40 and the oil chamber 41 are separated by avertically extending baflie 43, the upper end of which aligns with thebaffle 25 of the head. All three of these chambers open through the topof the bowl with the collection chamber 40 communicating with thechannel 24, the oil chamber 41 com-' municating with the cavity 33 andthe oil passage 42 communicating with the threaded passageway 32. Thebowl 12 is secured to the head by the assembly ring 13 the lower portionof which has an inturned flange to engage a peripheral flange at the topof the bowl. The assembly ring 13 is threaded and engages suitablethreading on the head to clamp the bowl to the head. To prevent leakagebetween the bowl and head, a gasket 44 is provided, entirely encirclingthe body of the bowl. A second gasket 45 prevents leakage between thecollection chamber 40 and the oil chamber 41 at the joint between thehead and the bowl. A third gasket 46 provides an air and oil tight sealbetween the oil chamber 41 and the oil passage 42 at the joint betweenthe head and bowl. These gaskets may be of any suitable type such as anO-ring.

The collection chamber 40 has, at its upper end, a funnel 50 throughwhich particles and water removed from the air by the filter 16 aredischarged into the collection chamber (Figs. 2 and 4). upper rimportion 51 divided into separate segments by means of a plurality ofslots 52. The slots 52 permit the rim portion 51 to be slightlycompressed as the funnel is inserted into the upper end of thecollection chamber 40. This compression causes the funnel to grip thewalls of the chamber firmly, thus holding it in position. Where it isdesired to positively prevent any possibility of the funnel slippingfurther into the chamber, the upper portion of the chamber 40 may bemade of a slightly greater diameter than the lower portion, creating ashoulder 53 (Fig. 2), serving as a stop for the funnel.

It sometimes happens, especially when the air system is first operated,that a large quantity of water will be discharged into the collectionchamber. To prevent this water from being held in the funnel 50 bytrapped air beneath, the slots 52 are extended into the inclined portionof the funnel to serve as air escape ports.

A drain or cleanout port 54 is provided at the bottom of the collectionchamber 40. The cleanout port 54 is surrounded by an internally threadedinsert 55 through which passes the drain cock fitting 56. A valve stem57, having a wing nut type grip, is threaded into the fitting 56 andserves as the actual shut off member.

The oil chamber 41, in the embodiment shown, is generally half-moon inshape. It is substantially larger than the collection chamber 40 (Fig.3). At its upper end it communicates with'the cavity 33 in the head. Atits lower end, it is provided with a drainage and cleanout port 58surrounding which is an internally threaded insert 59 for mounting thedrain cock 60. Like the drain 56, the drain cock 60 is locked inposition by a locking nut 61.

Access for the purpose of filling the oil chamber 41 The funnel has an,

4 may be had Without separating the bowl 12 from the head 11 by means ofthe filler port in the head closed by the cap member 62 (Fig. 1). Uponremoval of the cap 62, oil may be poured into the oil chamber 41.

The oil passage 42 is, in effect, a vertical tube to one side of the oilchamber 41, communicating with the oil chamber 41 by means of the bottomoffset portion 63 and separated from the main portion of the oil passage42 by the check valve 64. The check valve consists of a centrallyapertured restricting baffle 65 between the upper and lower portions ofthe oil passage 42. This bafile, at its upper end, has a valve seat 66.A ball valve 67 is normally seated on the valve seat 66. The upperportion of the oil passage 42 communicates with the threaded passage 32in the head 11.

The bowl 12 may be made from any suitable material but preferably it isfabricated of a transparent plastic, thereby providing visualobservation of the oil level in the oil chamber 41. It will berecognized that other materials may be used for fabrication of the bowl12 without departure from the principles of this invention.

To facilitate proper'indexing of the bowl 12 to the head 11, one or morelocating pins 68 may be provided (Fig. 2).

C. Regulator valve The baffle 25 has an aperture 70 extending throughit. Seated in this aperture is the regulator valve assembly 71 (Fig. 2).The details of regulator valve assembly 71 may be more clearly seen byreference to Figs. 6 and 7.

The regulator valve assembly includes an external, tubular sleeve 72press-fitted into the aperture 70 in the bafiie 25. Press-fitted intoone end of the sleeve 72 is a centrally apertured, first end plug 73,having on its inside face a valve seat 74 surrounding the centralaperture 75. Cut into the valve seats 74 are one or more by-pass slots76. These slots are of very small cross section to permit only a minutefiow of air around the ball valve 77 when the ball valve is seated.

Press-fitted into the opposite end of the sleeve 72 is a second,centrally apertured, end plug 78, having a central passageway 79 at theinner end of which is a valve seat 80. The valve seat 80, like the valveseat 74, has at least one by-pass slot 81 to permit the gradual flow ofair around the ball valve 77 when it is seated against the valve seat80.

The second end plug 78 forms an annular channel 82 into which is seatedone end of a coiled spring 83. The coil spring 83 presses against theball valve 77 and biases it toward the first end plug 73. However, uponany appreciable pressure differential acting in the opposite direction,the ball will be caused to shift from the valve seat 74 to valve seatagainst the resistance of the spring 83. The purpose of this will bebrought out more fully hereinafter.

The regulator valve assembly 71 is so mounted in the aperture 70 thatthe first end plug 73, towards which the ball valve 77 is normallybiased, is adjacent the collection chamber 40. While the aperture 70 isshown as inclined, this is not functionally necessary, it being merelyto provide access for machining the aperture 70.

D. The oil feeder The oil feeder has an externally threaded shell 91within the upper portion of which is a central chamber 92 openingthrough the upper end of the shell (Fig. 8). The central chamber 92communicates with the lower end of the oil feeder by means of a centralpassageway 93 extending from the bottom of the chamber through thebottom end of the shell. At its lower end, the shell is provided with atool slot 96 to facilitate its installation and subsequent adjustment.Seated within the chamber 92 is an elongated, annular restrictor sleeve94, extending through the center of which is an opening forming aopening 95 communicates with the upper end of the channel 93 in thelower end of the shell 91.

The restrictor sleeve 94 may be made of any suitable, porous materialsuch as a sintered metal, porous ceramic, felt or resin stabilized,cellulosic fibers such as paper or cloth. The restrictor must becharacterized by its ability to pass oil from the reservoir 95 to itsexternal surface in small quantities by either-percolation or capillaryaction. It is not intended that this invention should be restricted bythe particular material chosen for the restrictor, the limitations beingupon the capacity of the material to permit the restrictive flow ofthelubricant from the chamber 95 to the external surface of the restrictor.It is, however, important that the material be capable of preventing theflow of oil across its thickness when there is no pressure differentialbetween the inside and outside of the restrictor such as occurs when airis not flowing in the air passage 14.

With the restrictor sleeve 94 installed within the chamber 92, the upperend of the chamber is closed by means of a cap 97 press-fitted onto theshell 91. Preferably the cap 97 is slightly smaller in diameter than theshell 91 and is not threaded, whereby it will not interfere withinstallation of the oil feeder in the threaded pas sage 32.

The walls of the shell 91 are breached by at least one-axiallyextending, narrow slot 98. In the particular arrangement shown, twodiametrically positioned slots 98 are utilized. It will be understoodthat the number of slots employed will depend upon the minimum quantityof oil it is desired to discharge from the oil feeder into the airstream. The greater the minimum desired, the greater the number ofslots. The slots 98 extend through the walls of the shell 91 and providedirect communica tion between the air passage 14 and the externalsurface of the restrictor sleeve 94 by which oil may be withdrawn fromthe external surface of the restrictor into the air stream in the airpassage 14. These slots normally extend from the lower surface of thecap almost to the bottom of the chamber 92.

While a narrow slot is one of the most effective ways of providing alubricant discharge opening in the side of the shell 91, it is not theonly type of opening having utility in this invention. A plurality ofsmall holes, preferably arranged in a pattern axially of the shell maybe substituted for the slot. Other types of openings may be employed iftheir use is advantageous.

Where one or two openings are used in the shell such as the slots 98, itis entirely possible to effectively restrict the rate of flow of the oilsimply by covering the slots with strips of the same type of materialfrom which the restrictor sleeve 94 is manufactured.

E. Modifications Fig. shows a modified structure for the check valve 64.In check valve 64a, the restricting bafile 65a at the lower end of theoil passage 42a has a substantially larger central opening than existsin the baflle 65. An insert 100 having a valve seat already machinedinto it is press-fitted into the opening in the baffle 65a. Thisarrangement has the advantage of permitting the valve seat to beprecisely machined to close tolerances as a separate part where such anoperation is readily accessible. In the arrangement illustrated in Fig.2, the valve seat 66 is at the far end of a long passage making itdifficult to use tools accurately at this point. Thus, a tight fitbetween the ball valve 67 and its seat is difficult to obtain. Further,in the illustrated modification, the ball is biased against the seat 67by a very light coil spring 101, the lower end of which bears againstthe ball valve 67 and the upper end against the bottom of the oil feeder90. The spring 101 serves to positively seat the ball 67 even though thecolumn of oil trapped in the oil passage 42a is so short that the ballsWeight combined with that of the oil column may, at times,

be insufficient to form a fluid tight seal between the ball valve andits seat.

Fig. 11 illustrates another modification of the check valve. In thiscase the check valve assembly 64b is simi-v lar to the check valveassembly 64a inasmuch as the same restrictor baffle 65a and separatevalve seat insert are utilized. The same ball valve 67 is also utilized.However, the lower end of the oil passage 42b is of slightly smallerdiameter into the upper portion of which is press-fitted a centrallyapertured collar 102. The collar serves as the upper bearing member forthe coil spring 101a. By this arrangement, a much shorter coil springmay be utilized and thus the force with which it biases the ball valve67 against its seat may be more closely controlled.

Fig. 12 illustrates a modification in which the collection chamber 40aand the oil chamber 41a of the bowl 12a are not connected. This is doneby elimination of the aperture 70 through the baflle 25. In place of theaperture 70, a minute aperture is provided through the wall 111 in thehead, dividing the air passage 14 from the oil chamber 41a. The aperture110 communicates with the air passage 14 downstream of the filter 16 butupstream of the restricted throat 30. Thus, there will be a pressuredifferential between the air entering the oil chamber 41 through theaperture 110 and the air surrounding the oil feeder 90 due to theVenturi action of the throat 30. It will be seen from the followingdescription under the heading Operation that this pressure differentialis essential to the operation of this device. When this arrangement isused, it is unnecessary to utilize the collection chamber 40 in order toeffectively operate the lubricating unit.

Operation This invention is designed to be installed in an air linefeeding one or more pneumatically operated devices such as tools. Theair, under pressure, enters through the inlet port 23 and dischargesthrough the outlet port 31. Normally, the air entering the port 23 isunder a pressure of about 90 p.s.i. While this is the conventionalpressure rating at which devices of this type operate, it is notessential that this particular pressure be utilized. Practically theentire volume of air entering through the inlet port 23 passes throughthe filter 16 and discharges through the discharge port 31. Due to theresistance of the filter 16, a pressure drop of approximately /2 to 1p.s.i. occurs across the filter. Any water and foreign particles presentin the entering air are removed by the filter. Because of the slopingwalls of the filter, these particles are urged to discharge through theupstream end of the filter through the funnel 50 into the collectionchamber 40.

Conventional air filters employed in supply lines for tools have thefilter mounted at a right angle to the primary air stream. This requiresthe air to traverse a first right angle bend to reach the filter and totraverse at least two more sharp turns, which may or may not be a full90 degrees, in passing through the filter. Thereafter, the air must turn270 degrees in order to return to the passageway before discharging fromthe filter unit. Air, like all other fluids, resists such radicalchanges in flow direction. As a result an appreciable amount of theenergy of the air is lost in traversing the tortuous path, this lossbeing expressed as a pressure drop. By the utilization of an inline oraxial filter as employed in this invention, this energy loss or pressuredrop is markedly reduced since the air need only traverse the twodirectional changes necessitated by its passage through the walls of thefilter. Thus, the unit illustrated in this invention, is, for thisreason alone, a marked improvement over and substantially more eflicientthan the conventional units now in operation. This reduction in pressuredrop means greater efficiency in the tools operation because it requiresa smaller volume of air to develop a given torque value. However, it isimportant that a cor- 7 tain amount of pressure differential does occuracross the filter in order to operate this invention, particularly ifthe restricted throat 30 is not employed. This will be discussed morefully hereinafter.

The water and solid particles removed from the air by the filter 16 aredischarged into the collection chamber 40. These periodically can beremoved by flushing or any other suitable method when the drain cock 56is opened.

The oil chamber 41 serves as an oil reservoir. The volume of oil in thechamber can easily be observed externally of the bowl if the bowl is ofa transparent material or is provided with a transparent panel. The oilin the chamber 41 will normally lift the ball valve 67 of the checkvalve 64 permitting it to fill the oil passage 42. Due to the weight ofthe ball, unless there is a pressure differential between the twochambers, the chamber 42 will not be filled to the same level as thechamber 41.

As soon as air under normal operating pressure is turned on, the airpassage 14 becomes filled. Immediately the collection chamber 40 will befilled with air under pressure. This air will pass through the regulatorvalve '71 to place the air above the oil in the oil chamber 41 under asimilar pressure. This will upset the check valve 64, causing not onlythe passageway 42 to be filled, but forcing oil up into the reservoiropening 95 of the restrictor 94. This reservoir will be entirely filledand any air trapped in its upper end will be discharged by percolationthrough the walls of the restrictor 94. If this does not occurimmediately it will occur as soon as the tool is turned on and airstarts flowing through the air passage 14. This occurs because of apressure differential between the air bearing down on the surface of theoil in the oil chamber 41 and the air pressure surrounding the end ofthe oil feed 90, projecting into the air passage 14. This pressuredifferential is due either to the pressure drop across the filterelement 16 or to the Venturi action of the restrictor 30 or both. Thegreater this difference, the more forcibly the oil will be pressed upinto the reservoir 95.

When the system becomes stabilized by the oil chamber 42 being filledand the air pressure in both the oil chamber 41 and the collectionchamber 40 being equalized, the ball valve 77 of the regulator valve 71will seat under the urging of the spring 83 against the end insert 73.So long as the machine is operating normally, the ball will remain inthis position. Oil will be gradually completely withdrawn through theoil feeder 90 into the air stream. As this oil is withdrawn it will bereplaced by oil from the oil chamber 41. By means of the bypass slots 76in the seat 74 of the regulator valve 71 air will be admitted to the oilchamber to compensate for the volume of oil discharged through the oilfeeder 90. Since the rate of discharge of oil through the oil feeder isnormally very small, being in the neighborhood normally of approximately0.10 ounce per hour, the minuteness of the slot 76 will not interferewith the entrance of adequate quantities of air to stabilize thepressure in the oil chamber.

For any reason, should a major imbalance occur between the collectionand oil chambers with the oil chamber having a pressure substantiallybelow that of the collection chamber the ball valve 77 will immediatelyshift to seat against the end insert 78 (Fig. 6). In so doing it willpermit a surge of air to pass through, normally sufficient tore-establish the equilibrium between the chamber. If the equilibrium isnot thus re-established, air will continue to bleed in to the oilchamber through the by-pass slots 81 to re-establish the equilibrium.Before this equilibrium is re-established, the ball will shift back toseat against the first end insert 73 under the urging of the spring 83.

This situation occurs when the oil chamber is opened for filling withoutthe air line supplying the device being shut off. In this case, the cap62 is loosened sufliciently to allow the air in the oil chamber 41 toescape. This quickly causes the ball valve 77 to shift. The cap 62 canthen be removed and the oil chamber 41 filled. The amount of airentering the chamber by way of the bypass slots 81 is so small that itwill not interfere with operation. When the chamber has been filled, thecap 62 is replaced and the continued flow of air through the by-passslots 81 will gradually re-establish equilibrium in air pressure betweenthe two chambers.

While the oil chamber is open for filling, the check valve 64 will seat,preventing escape of the column of oil in the passageway 42. Thisprovides a supply for the oil feeder during the filling operation. Theoil feeder 90 will continue to supply oil to the air stream inasmuch asthe reservoir within the restrictor 94 will be full and until thissupply is exhausted, effective lubrication will be maintained. Thereservoir capacity of the oil feeder and the rate of oil discharge aresuch that the oil feeder has a supply which will last many times thelength of the period necessary to fill the oil chamber 41. Afterfilling, the check valve 64 will usually open as soon as pressure isreestablished on the surface of the oil in the oil chamber to replacethe oil removed through the oil feeder 90 while the oil chamber 41 wasbeing filled. It is seen that this device thus permits the oil chamberto be filled and serviced without interrupting the operation of thetool, both because filling may be done without shutting off the airsupply and without interfering with the discharge of lubricant into theair stream.

Since the oil feeder 90 is externally threaded, it is verticallyadjustable within the threaded passage 32. A lesser or greater length ofthe oil feeder 90 may be exposed in the air passage 14. This, of course,will determine the length of the slot 98 exposed to the wiping action ofthe air passing through the air passageway and thus the volume of oildischarged into the air stream. This adjustment must be made before thebowl is attached to the head. This being the case, this adjustmentcannot be changed by the operator during the operation of the tool.

In the oil feeder 90, were the restrictor not present, the oil would berapidly removed in large quantities through the slot 98. The restrictorfunctions to prevent the discharge of excess quantities of oil into theair stream. Since only that portion of the restrictor exposed throughthe slot is available for wiping, the rate of discharge is effectivelycontrolled. It will be recognized that the function of the restrictorcan, to some extent, be performed by the utilization of a few minuteopenings in the wall of the shell 91. Such an arrangement, however, isfar less satisfactory because such openings have a tendency to becomeblocked by even minute foreign particles, interfering with the rate oflubrication and endangering expensive equipment. Further, such orifices,unless they are of capillary size, will permit the slow discharge of oilinto the air passage 14 when the air stream in the passageway is notoperating. Both of these difficulties are overcome by the use of theporous restrictor sleeve. Further, the porous restrictor is lessexpensive to manufacture than an element having the minute orifices.

The porous member 94 of the restrictor also serves as a filter for theoil, removing all traces of foreign matter which may be present.

It will be recognized that in some operations the use of the collectionchamber 40a may be considered unnecessary. In this situation the airpressure differential necessary to force the oil from the oil chamber41a into the oil passage 42 (Fig. 12) may be supplied directly from theair passage 14 by the use of the orifice 110. With the orifice placed onthe downstream side of the filter 16, a pressure differential will occurbetween the air in the oil chamber 41a and the air surrounding the oilfeeder 90 due to the Venturi action of the throat 30. This will besufficient to induce oil to form a column in the oil passage 42 and tofill the reservoir within the oil feeder 90. In the arrangementshown inFig. 2 the use of a restricted throat between the filter 16 and thedischarge port 31 is not essential, since sufiicient pressuredilferential normally occurs across the filter 16 to operate thelubricating mechanism. However, in the construction shown in Fig. 12,the restricted throat 30 is essential to create the necessary pressuredifierential. It is entirely possible in this device to eliminate thefilter 16 and to supply air directly from the passage 14 ahead of therestricted throat 30 to the oil chamber 41a. In this case the devicewould serve purely and simply as a lubricator. In those situations inwhich the filter is used but the air is introduced to the oil chamberfrom an orifice communicating with the passageway 14 ahead of the filterthe restricted throat 30 can be eliminated. Each of these particulararrangements is no more than a modification of this invention embodyinga portion of its principles and permitting the invention to be adaptedto particular job requirements.

It will be recognized that these and other modifications of thisinvention may be made each without departing from the principlesdisclosed herein. Each of these modifications is to be considered asincluded in the hereinafter appended claims unless these claims by theirlanguage expressly state otherwise.

I claim:

1. An oil feeder and restrictor comprising: a hollow housing; a tubularinsert of porous material seated within said housing, said insert havinga central reservoir therein, the inner surface of said insert formingthe wall of said reservoir; a restricted orifice through said housingproviding communication between the outer surface of said insert and theambient atmosphere exterior of said housing.

2. An oil feeder and discharge rate regulator comprising: a tubularhousing closed on one end; a slot in the side wall of said housing; asleeve of porous material received into said housing, said sleeve beingexposed through said slot; said sleeve being tubular and having acentral oil reservoir, the inner surface of said sleeve forming the wallof said reservoir; one end of said reservoir being open for receivingoil; said reservoir extending axially of said sleeve at least to becoplanar with said slot.

3. In a lubricator having a housing, said housing having an air passageand an oil passage communicating with said air passage, the combinationcomprising: a shell having a side aperture seated in said oil passage;an elongated sleeve of porous material seated in said shell; said sleevebeing tubular and defining a central oil reservoir characterized by aporous wall; means closing one end of said reservoir; the portion ofsaid shell having said aperture and a portion of said sleeve includingboth said end closing means and a portion of said reservoir projectinginto said air passage; said reservoir extending axially of said sleeveat least to be coplanar with said aperture; said sleeve being axiallyadjustable in said oil passage; means in said housing adapted tomaintain a column of oil in said reservoir.

4. In a lubricator having a housing, said housing having an air passageand an oil passage communicating with said air passage, the combinationcomprising: an elongated sleeve of porous material; said sleeve beingtubular and defining a central oil reservoir characterized by a porouswall; a shell enclosing said sleeve; one end of said shell and sleeveincluding a portion of said reservoir projecting into said air passage,said one end being apertured to provide communication through said shellbetween the outer surface of said sleeve and said air passage; said oilreservoir extending axially of said sleeve at least to be coplanar withsaid aperture in said shell; the other end of said shell being open;means in said housing adapted to maintain a column of oil in saidreservoir through said other end of said shell.

5. In a lubricator having a housing, said housing having an air passageand an oil passage communicating with said air passage, the combinationcomprising: an elongated sleeve of porous material encompassed by ashell having an aperture in its side wall; said sleeve being tubular andextending over said aperture and thus forming a central oil reservoircharacterized by a porous wall; means on said shell closing one end ofsaid reservoir; said shell mounted in said oil passage and having itsclosed end extending into said air passage sufiiciently to expose atleast a portion of said aperture and thus the exterior surface of saidsleeve to the air in said air passage; and means in said housing adaptedto maintain a column of oil in said reservoir at least to the level ofsaid aperture.

References Cited in the file of this patent UNITED STATES PATENTS1,358,928 Boehm Nov. 16, 1920 1,956,644 Hamerly May 1, 1934 2,084,998Bijur June 29, 1937 2,680,496 Johnson June 8, 1954 2,735,512 Faust Feb.2, 1956 FOREIGN PATENTS 487,567 France July 12, 1918

